900 g water
475 g sugar
2-4 lemons, juice (or: 6-8 g citric acid)
approx 250 ml (closely packed) fresh lavender spikes; don't remove the leaves
Mix water and sugar, bring to a boil, cook a few minutes. Take from heat, let cool a few minutes (to approx 85 deg C), then put in the lavender. Cut surfaces of the stems should not be covered by liquid. Let cool until lukewarm. Add lemon juice (color will change from pale blue to pink). Let soak for some hours more. Remove lavender, pour syrup through a fine sieve, fill into bottles and seal.